DOA estimation of nonstationary sources with time-frequency maximum likelihood method

Direction finding of nonstationary signals using an antenna array is of growing interest in. the signal processing community. We develop a time-frequency maximum likelihood method based on cross pseudo Wigner-Ville distributions (PWVDs) between the array signal vector and the satellite sensor output to obtain the DOA estimates. Compared with methods based on STFD (spatial time-frequency distribution) matrices, the proposed method can make full use of the crossterm TFDs between sources, and signal selective direction finding can be realized with much simpler computation. Moreover, the proposed method can handle signals with the same time-frequency signature. Numerical simulations are provided to demonstrate the validity of the method.